Wiper blade



A. B. KEMPEL WIPER BLADE Aug. 24, 1937.

Filed Aug. 14, 1936 `Patented Aug. 24, 1937 UNITED STATES PATENT .OFFICE WIPER BLADE Arthur B. Kempel, East Brady, Pa., assignor, by mesne assignments, to Raymond A. Rodrick, Akron, Ohio Application August 14, 1936, Serial No. 96,064

1 Claim. (Cl. 15-245) This invention relates to squeegees or cleaner ed in a laterally-extended at form as illustrated blades for windshields etc., of the type including in Figs. 2 and 3, and adapted to be bent into tubua hollow, ilexible, rubber cleaner element which lar form and assembled with the holder as shown may be formed with longitudinal wiping ribs. in Figs. 1 and 4. Said strip is provided with 5 My principal object is to increase the durathickened marginal anchoring portions I2, somebility of the rubber element in such devices. In what wedge-shaped in section, for reception bethe prevailing form of this type of cleaner, there tween the sides of the holder I0, in which they is a channel-shaped metal blade back or holder, are held under a slight compression, and on the and the rubber element is a strip bent into tububack it is formed with a pair of wedge-shaped lar form and having thickened marginal anchorribs I3 overlapping said thickened portions and 10 ing portions which are brought together and held inwardly terminating in abrupt shoulders I4 bein the metal channel. 'I'he comparatively thin tween the anchoring portions and. the flexible wall of the intermediate flexing portion has heremiddle portion of. the rubber element, said ribs tofore been made of substantially uniform thickmeeting to define the Xed portion 0f the tube ness throughout its width. This produced a wall on the holder side and to aid in maintaining 15 rather sharp bending or hinging action at the the compression of the anchoring portions. The edges of said flexing portion where it joins the intermediate part l5 of the rubber element, bethickened marginal portions, as the blade is moved tween the shoulders I4, constitutes the flexing back and forth over the glass, and ultimately, in portion of said element.

0 many instances, the rubber would split longi- On the side of the strip II which is to form its 2o tudinauy at these places and ruin the blade or acting face, it is molded with a series of parallel decrease its efficiency. That objection is remedied longitudinal ribs I6 extending for the full length by the present invention. of said strip and anked by separating grooves I'l,

Of the accompanying drawing, Fig. lis a vertithe two marginal ones of which underlie the cal side elevation showing a preferred form of wedge-shaped ribs I3. In accordance with my in- 25 wiper blade embodying my invention. vention, the wall of the ilexing portion I5, form- Fig. 2 is an enlarged end view of the rubber ing the bottom wall portions of the grooves I1, element extended in the flat form in which it is is graduated or substantially tapered in cross molded, section, from a greater thickness at the margins Fig. 3 is a back plan view of one end of said of said iiexing portion, to a smaller thickness 30 extended rubber element on the same scale as at the middle thereof, in order to distribute the Fig. 2. bending or hinge action at the margins, result- Fig. 4 is an enlarged cross-section on the line ing from the back-and-forth movement of the 4-4 of Fig. 1. wiper across the windshield glass, instead of con- The particular wiper here illustrated is perfocentrating it at the corners I8, as happens when 35 rated in the tread or wiping portion of its rubthis iiexing wall is made of uniform thickness ber element in order to drain the grooves thereof` throughout. partly through the interior of said element, and to Since the thickness at the ribs is uniform, this supply upon the glass an anti-freeze substance graduation makes the ribs I6 of varying height from the interior through the perforations in and the grooves I1 of different depths, the one 40 freezing or sleety Weather, but the invention also or ones in the middle being the deepest. The five applies to non-perforated tubular or hollow middle grooves, for example, may be of uniform wipers. depth and their bottom walls Ila of the minimum In the drawing, l 0 is the channel-shaped back thickness such as .02, the next one on each side or holder of the cleaner blade, made of sheet of shallower depth and its bottom wall IlD of a 45 metal and with its side portions inclined toward greater thickness-such as .03, the next or last each other and outwardly flared at their edges but one on each side of still shallower depth and to grip the anchoring portions of the rubber eleits bottom wall Ilc of a still greater thickness ment. Said holder may be provided with any such as .04", and the last groove on each side of suitable form of rearwardly projecting clip or the same depth as its neighbor. Thus the illus- 50 coupling member, not here illustrated, for attration shows ten full ribs I6 and eleven grooves taching it to the wiper arm mounted on the wind- I1, covering the full width of the flexing portion i shield, or may be otherwise adapted for connec- I5 and having the described graduation of wall tion with such an arm. thickness, but it will be understood that a greater II is the rubber wiping element, which is moldor less number of ribs and grooves may be pro- 55 vided, and only two of said ribs :s in the mustrated arrangement, or four at the most, are generally active in the wiping operation. A ribbing of the entire exposed outer surface provides a desirable combination of flexibility and durability oi said exposed portion, and it has been found that the described graduation of wall thickness prevents the cracking or splitting of the wall margins heretofore experienced at the corners I8.

'The rubber element is further shown as provided with a multiplicity of perforations I 9, which may be in one or more longitudinal rows, three in this instance, located at the bottom of the middle groove or grooves Il. A considerable middle length of the strip wall at each end, for about is left unperforated as indicated at 20, to resist the twisting eifect where said end portions may overlap the windshield frame at the ends of the blade stroke. It has been found desirable to make the solid rubber partitions or struts 2| between adjacent perforations i9 of a certain minimum length, such as approximately two millimeters, to avoid breaking of said struts. These perforations serve to drain the grooves l1 partly through the hollow interior of the wiper and out through the end thereof during a heavy rainfall, and thus to decrease the thickness of the water lm between the glass and the active ribs. 'Ihe effect of confining the perforations I8 substantially to those groove bottoms adjacent to the active ribs I6 is to promote a attening and greater exibility of the tread wall, and thus to enhance the described eiect of thickening the adjacent marginal portions of the flexing wall in preventing an objectionable hinging action at the corners I8.

It will be understood that the described form of embodiment may be more or less varied Without departing from the scope of my invention as defined in the claim.

I claim:

A windshield wiper blade comprising a holder, and a. hollow rubber wiping element having marginal anchoring portions mounted in said holder and an intermediate flexing portion, the latter being longitudinally ribbed and perforated adjacent the ribs, in the glass-contacting middle portion thereof, and longitudinally ribbed and substantially unperforated in its marginal portions, and being graduated from a maximum Wall thickness in said marginal portions adjacent to the holder to a minimum thickness in said middle perforated portion.

ARTHUR B. KEMPEL. 

